/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.activiti.rest.service.api.runtime.task;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiParam;
import io.swagger.annotations.ApiResponse;
import io.swagger.annotations.ApiResponses;
import io.swagger.annotations.Authorization;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.ActivitiObjectNotFoundException;
import org.activiti.engine.task.IdentityLink;
import org.activiti.engine.task.Task;
import org.activiti.rest.service.api.RestUrls;
import org.activiti.rest.service.api.engine.RestIdentityLink;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

/**

 */
@RestController
@Api(tags = { "Tasks" }, description = "Manage Tasks", authorizations = { @Authorization(value = "basicAuth") })
public class TaskIdentityLinkResource extends TaskBaseResource {


  @ApiOperation(value = "Get a single identity link on a task", tags = {"Tasks"}, nickname = "getTaskInstanceIdentityLinks")
  @ApiResponses(value = {
      @ApiResponse(code = 200, message =  "Indicates the task and identity link was found and returned."),
      @ApiResponse(code = 404, message = "Indicates the requested task was not found or the task doesn’t have the requested identityLink. The status contains additional information about this error.")
  })
  @RequestMapping(value = "/runtime/tasks/{taskId}/identitylinks/{family}/{identityId}/{type}", method = RequestMethod.GET, produces = "application/json")
  public RestIdentityLink getIdentityLink(@ApiParam(name="taskId", value="The id of the task .") @PathVariable("taskId") String taskId,@ApiParam(name="family", value="Either groups or users, depending on what kind of identity is targeted.") @PathVariable("family") String family,@ApiParam(name="identityId", value="The id of the identity.") @PathVariable("identityId") String identityId,
      @ApiParam(name="type", value="The type of identity link.") @PathVariable("type") String type, HttpServletRequest request) {

    Task task = getTaskFromRequest(taskId);
    validateIdentityLinkArguments(family, identityId, type);

    IdentityLink link = getIdentityLink(family, identityId, type, task.getId());

    return restResponseFactory.createRestIdentityLink(link);
  }

  @ApiOperation(value = "Delete an identity link on a task", tags = {"Tasks"}, nickname = "deleteTaskInstanceIdentityLinks")
  @ApiResponses(value = {
      @ApiResponse(code = 204, message = "Indicates the task and identity link were found and the link has been deleted. Response-body is intentionally empty."),
      @ApiResponse(code = 404, message = "Indicates the requested task was not found or the task doesn’t have the requested identityLink. The status contains additional information about this error.")
  })
  @RequestMapping(value = "/runtime/tasks/{taskId}/identitylinks/{family}/{identityId}/{type}", method = RequestMethod.DELETE)
  public void deleteIdentityLink(@ApiParam(name = "taskId", value="The id of the task.") @PathVariable("taskId") String taskId,@ApiParam(name = "family", value="Either groups or users, depending on what kind of identity is targeted.") @PathVariable("family") String family,@ApiParam(name = "identityId", value="The id of the identity.") @PathVariable("identityId") String identityId,@ApiParam(name = "type", value="The type of identity link.") @PathVariable("type") String type,
      HttpServletResponse response) {

    Task task = getTaskFromRequest(taskId);

    validateIdentityLinkArguments(family, identityId, type);

    // Check if identitylink to delete exists
    getIdentityLink(family, identityId, type, task.getId());

    if (RestUrls.SEGMENT_IDENTITYLINKS_FAMILY_USERS.equals(family)) {
      taskService.deleteUserIdentityLink(task.getId(), identityId, type);
    } else {
      taskService.deleteGroupIdentityLink(task.getId(), identityId, type);
    }

    response.setStatus(HttpStatus.NO_CONTENT.value());
  }

  protected void validateIdentityLinkArguments(String family, String identityId, String type) {
    if (family == null || (!RestUrls.SEGMENT_IDENTITYLINKS_FAMILY_GROUPS.equals(family) && !RestUrls.SEGMENT_IDENTITYLINKS_FAMILY_USERS.equals(family))) {
      throw new ActivitiIllegalArgumentException("Identity link family should be 'users' or 'groups'.");
    }
    if (identityId == null) {
      throw new ActivitiIllegalArgumentException("IdentityId is required.");
    }
    if (type == null) {
      throw new ActivitiIllegalArgumentException("Type is required.");
    }
  }

  protected IdentityLink getIdentityLink(String family, String identityId, String type, String taskId) {
    boolean isUser = family.equals(RestUrls.SEGMENT_IDENTITYLINKS_FAMILY_USERS);

    // Perhaps it would be better to offer getting a single identitylink
    // from the API
    List<IdentityLink> allLinks = taskService.getIdentityLinksForTask(taskId);
    for (IdentityLink link : allLinks) {
      boolean rightIdentity = false;
      if (isUser) {
        rightIdentity = identityId.equals(link.getUserId());
      } else {
        rightIdentity = identityId.equals(link.getGroupId());
      }

      if (rightIdentity && link.getType().equals(type)) {
        return link;
      }
    }
    throw new ActivitiObjectNotFoundException("Could not find the requested identity link.", IdentityLink.class);
  }
}
